Catalytic Removal of N-Allyloxycarbonyl Groups Using the [CpRu(IV)(π-C3H5)(2-quinolinecarboxylato)]PF6 Complex. A New Efficient Deprotecting Method in Peptide Synthesis

A variety of amines including even sterically less demanding and highly nucleophilic secondary amines have been efficiently deprotected without decarboxylative N-allylation from the corresponding N-allyloxycarbonyl (N-AOC) compounds by using a catalytic amount of [CpRu(IV)(π-C3H5)(2-quinolinecarboxylato)]PF6 in the presence of 1 molar amount of trifluoromethanesulfonic acid, the general utility of which has been demonstrated by the efficient synthesis of a collagen protein unit tripeptide, Pro-Pro-Gly.